adrenergic agonist

(redirected from adrenoreceptor agonist)

adrenergic agonist

A family of agents which have adrenaline-like effects, acting directly or indirectly on any of the five G-protein-coupled adrenergic receptors: apha1, alpha2, beta1, beta2, beta3.

Actions of adrenergic agonists
alpha1 receptors: Activate phospholipase C (via Gq), increasing protein kinase C activity.
alpha2: receptors Inhibit adenylate cyclase (via G1), decreasing protein kinase A activity.
beta receptors: Activate adenylate cyclase (via Gs), increasing protein kinase A activity.

adrenergic agonist

Any of a group of therapeutic agents, e.g. epinephrine, that mimic or stimulate the sympathetic nervous system.
See also: agonist

sympathomimetic drugs 

Drugs that produce an effect similar to that obtained by stimulation of the sympathetic nervous system. Some of these predominantly act on the adrenergic alpha-receptors (e.g. noradrenaline (norepinephrine)), while others act on the adrenergic beta-receptors (e.g. isoproterenol). Others have little direct effect on the adrenergic receptors but enhance the release of natural catecholamine from the sympathetic nerve terminals (e.g. amphetamine, phenylpropanolamine). Sympathomimetic drugs are used (1) in the treatment of open-angle glaucoma by decreasing aqueous humour secretion and increase the outflow through the trabecular meshwork thus reducing the intraocular pressure (e.g. adrenaline (epinephrine), apraclonidine, dipivefrine hydrochloride, brimonidine tartrate), (2) dilate the pupil without affecting accommodation (e.g. phenylephrine) and (3) constrict conjunctival blood vessels (e.g. naphazoline, tetrahydrozoline). Syn. adrenergic agonist; adrenergic stimulating agent. See alpha-adrenergic agonist; mydriatic.

ad·re·ner·gic ag·o·nist

(adrĕ-nĕrjik agŏ-nist)
An agent capable of combining with receptors to initiate actions of or like epinephrine.
See: agonist
See also: epinephrine
References in periodicals archive ?
Midodrine, an a1 adrenoreceptor agonist, can act on the a1 adrenergic receptor, constricting the vessels, so as to lessen the symptoms of POTS.
[2] Alpha 2 adrenoreceptor agonist are found to have antinociceptive action for both somatic and visceral pain [3,4] Clonidine is already established as adjuvant to Bupivacaine in regional anaesthesia.
It has been estimated that each year over 7 million veterinary patients use a-2 adrenoreceptor agonist as part of their anesthetic protocol (Maze and Trangilli 1991).
(2) The action of one drug is prevented by a second drug acting on a separate part of the signalling pathway, eg verapamil prevents entry of calcium into myocardial cells and will counter the effects of dobutamine (a beta-1 adrenoreceptor agonist).
The Foradil Aerolizer (formoterol inhalation powder), a long-acting, selective [beta]-2 adrenoreceptor agonist manufactured by Novartis Pharmaceuticals Corp., is indicated for the scheduled maintenance therapy for asthma and COPD and for the prevention of exercise-induced bronchospasm on an as-needed basis.
The Foradil Aerolizer (formoterol inhalation powder), a long-acting, selective [beta]2 adrenoreceptor agonist manufactured by Novartis Pharmaceuticals Corp., is indicated for the scheduled maintenance therapy for asthma and COPD and for the prevention of exercise-induced bronchospasm on an as-needed basis.
Clonidine, an alpha-2 adrenoreceptor agonist has been shown to attenuate the cardiovascular response during laryngoscopy and intubation by various workers.
Dexmedetomidine is a selective [alpha]-2 adrenoreceptor agonist. It is fast becoming a popular anaesthetic adjuvant for sedative, anxiolytic, analgesic and sympatholytic actions.
Patients on adrenoreceptor agonist or antagonist therapy with known hypersensitivity to local anaesthetic drugs, bleeding disorders, uncontrolled diabetes mellitus, pregnant women and pre-existing peripheral neuropathy were excluded from the study.
Dexmedetomidine also a [alpha]-2 adrenoreceptor agonist is pharmacologically related to clonidine and is a highly specific and selective alpha-2 adrenoreceptor agonist with 8 times more affinity for alpha-2 adrenoreceptor than clonidine.
(10,11,12) Studies have been published regarding the attenuation of haemodynemic response by [alpha]-2 adrenoreceptor agonist clonidine.
(3) Dexmedetomidine a highly selective [alpha]-2 adrenoreceptor agonist has gained popularity and is being used in various procedures in the perioperative and critical care settings.